KR101709637B1 - Method and apparatus - Google Patents

Abstract

The method includes receiving signal information for at least one cell from a plurality of user equipments, and using the information to determine whether a candidate cell is entering a reduced power mode.

Description

METHOD AND APPARATUS [0001]

Embodiments are directed to methods and apparatus, and more particularly, but not exclusively, to methods and apparatus for determining whether a cell can be used in a reduced energy mode.

A communication system may be understood as a facility that enables communication sessions between two or more entities, such as mobile communication devices and / or other stations associated with a communication system. Communication systems and compatible communication devices generally operate in accordance with a given standard or specification that suggests what the various entities associated with the system are allowed to do and how it should be accomplished. For example, the manner in which a communication device can access a communication system and how communications are to be implemented among the devices that communicate, the elements of the communication network, and / or other communication devices is generally defined.
In a wireless communication system, at least some of the communications between at least two stations occur over a wireless link. Examples of wireless systems include public land mobile networks (PLMN), satellite based communication systems, and other wireless local networks, e.g., wireless local area networks (WLAN). In wireless systems, a network element or network entity (NE) or access node is provided by the base station. The wireless coverage area of a base station is known as a cell, and therefore wireless systems are often referred to as cellular systems. In some systems, for example in the 3GPP standard system, a base station access node is referred to as a Node B (NB) or an enhanced Node B (eNB).
The user can access the communication system by an appropriate communication device. The user's communication device is often referred to as user equipment (UE). A communication device is provided with a suitable signal receiving and transmitting device for enabling communications with other parties. A communication device may be arranged to communicate data for communicating communications, such as, for example, voice, electronic mail (e-mail), text messaging, multimedia for enabling Internet access, and the like. Accordingly, users can receive and receive a large number of services through their communication devices. A communication connection may be provided by one or more data bearers.
In wireless systems, a communication device provides a transceiver station capable of communicating with an access node and / or other communication device. The communication device or user equipment may also be considered to be part of a communication system. In some applications, for example in ad hoc networks, a communication system may be based on the use of a plurality of user equipments capable of communicating with each other.
Network management is a complex task. On the one hand, complexity arises due to the large number of network elements (NEs) that have to be developed and managed and on the other hand the interdependencies between the configuration and state of the deployed network elements in terms of performance, faults, . In heterogeneous networks, the various technologies being developed and their reselling paradigms are difficult to handle. Thus, the configuration, optimization, and troubleshooting of network management require a high degree of expertise and that operational management workflows are typically performed by human operators supported by software tools. However, this manual and semi-automatic management is time consuming, error-prone, and potentially costly because it can not respond quickly enough to network changes.
It was the goal of network management architects to try to automate operations, administration and management (OAM) functions by deploying "Self Organizing Networks" (SONs). SON concepts are generally applicable, but due to the large number of NEs (and hence the incurred costs for carrying out remote and on-site management activities) distributed over large geographical areas, The focus of which was on Radio Access Networks (RANs). In particular, long term evolution (LTE) and long term evolution (LTE) such as evolutionary universal mobile telecommunications system (UMTS) terrestrial radio access network (E-UTRAN) For LTE-A (LTE-advanced) radio access network (RAN) standards, SON is considered a useful building block due to the potential for high degree of distribution and heterogeneity. In such networks, there may be a wide range of telecommunications standards being used, such as simultaneous operation of 2G / 3G / LTE / LTE-A network elements. In addition, in a structure that utilizes LTE multi-layer structures where there may be picocells, microcells, and macrocells all operating over the same geographical range, for example, LTE networks may be of several different types.

According to one aspect, there is provided a method comprising: receiving signal information for at least one cell from a plurality of user equipments; And using the information to determine whether the candidate cell will enter a reduced power mode.
The signal information may be handover information.
The signal information may include at least one of signal strength information and signal quality information.
The signal information may include at least one of a reference signal reception power and a reference signal reception quality.
The method may comprise receiving, from each of the plurality of user equipments, signal information for a serving cell and at least one other cell different from the candidate cell.
The method may include receiving information about each neighboring cell in the candidate cell, wherein a determination is made as to whether the candidate cell is entering a reduced power mode.
The method may include using the received information to determine an outage probability for the user equipment when the candidate cell enters a reduced power mode.
The step of determining the power failure probability may depend on information about one or more user equipments receiving only signals from the serving cell.
If the electrostatic probability is below the threshold, the candidate cell may enter the reduced power mode.
The reduced power mode may include switching off the cell.
The method may include repeating the method such that if the candidate cell is determined not to enter the reduced power mode, at least one parameter of the at least one neighboring cell is changed and the method is repeated.
The at least one parameter may comprise at least one of an antenna configuration, antenna orientation, transmit power, and uplink power control parameters.
The method may be performed in a base station, a controller, an element manager, or a network management system.
A computer program containing program code means adapted to perform the method may also be provided. The computer program may be stored by a carrier wave medium and / or otherwise implemented.
According to another aspect, there is provided an apparatus comprising: means for receiving signaling information for at least one cell from a plurality of user equipments; And means for using the information to determine whether the candidate cell will enter a reduced power mode.
The signal information may be handover information.
The signal information may include at least one of signal strength information and signal quality information.
The signal information may include at least one of a reference signal reception power and a reference signal reception quality.
The means for use may be for comparing signal information for the at least one cell with a minimum value for the signal information.
The means for use may be for comparing signal information for the at least one cell with a minimum value for the signal information.
The means for receiving may receive, from each of the plurality of user equipments, signal information for a serving cell and at least one other cell different from the candidate cell.
The means for receiving may receive information about each neighboring cell in the candidate cell, wherein a determination is made as to whether the candidate cell falls into a reduced power mode.
The means for using may be for determining the power failure probability for the user equipment using the received information when the candidate cell enters the reduced power mode.
The means for use may be for determining the power failure probability according to information from one or more user equipment receiving only signals from the serving cell.
The means for use may be for causing the candidate cell to enter a reduced power mode if the electrostatic probability is below a threshold.
The reduced power mode may include switching off the cell.
The means for use may cause the at least one parameter of the at least one neighboring cell to change and repeat the method if it is determined that the candidate cell will not enter the reduced power mode.
The at least one parameter may comprise at least one of an antenna configuration, antenna orientation, transmit power, and uplink power control parameters.
According to another aspect, there is provided an apparatus comprising at least one processor and at least one memory comprising computer code for one or more programs, wherein the at least one memory and computer code cause the apparatus to: Receive signaling information for at least one cell from a user equipment; And to use the information to determine whether the candidate cell is entering a reduced power mode.
The signal information may be handover information.
The signal information may include at least one of signal strength information and signal quality information.
The signal information may include at least one of a reference signal reception power and a reference signal reception quality.
The at least one memory and computer code may be configured with at least one processor to cause the device to receive signaling information from each of the plurality of user equipments for a serving cell and at least one other cell other than the candidate cell .
At least one memory and computer code is coupled to at least one processor to cause the apparatus to receive information about each neighboring cell in the candidate cell in which a determination is made as to whether the candidate cell is entering a reduced power mode, ≪ / RTI >
The at least one memory and computer code may be configured with at least one processor to cause the apparatus to determine the probability of power failure for the user equipment using the received information when the candidate cell enters a reduced power mode have.
The at least one memory and computer code may be configured with at least one processor to cause the device to determine the probability of failure by determining one or more user equipments that receive only signals from the serving cell.
The at least one memory and computer code may be configured with at least one processor to cause the device to cause the candidate cell to enter a reduced power mode in accordance with a probability of power failure. In some embodiments, if the probability of electrostatic failure is below a threshold, the candidate cell may enter a reduced power mode.
The reduced power mode may include switching off the cell.
At least one of the memory and the computer code is coupled to the at least one processor to cause at least one parameter of the at least one neighboring cell to change and to repeat the analysis or method when it is determined that the candidate cell will not enter the reduced power mode. Lt; / RTI >
The at least one parameter may comprise at least one of an antenna configuration, antenna orientation, transmit power, and uplink power control parameters.
A base station, a controller, an element manager or a network management system may comprise the device.
Various other aspects and further embodiments are also described in the following detailed description and in the appended claims.

Embodiments will now be described in more detail by way of example only, with reference to the following examples and the accompanying drawings.
Figure 1 shows a schematic diagram of a network according to some embodiments.
Figure 2 shows a schematic diagram of a mobile communication device in accordance with some embodiments.
Figure 3 shows a schematic representation of a SON control device according to some embodiments.
Figure 4 shows the method of the embodiment.

여기서
Pr은 확률이다.
Pr(UE in outage|eNB_off)는 후보 eNodeB가 오프 전환되는 경우에 사용자 장비가 정전을 겪게 될 확률이다.
K는 폐쇄될 후보 셀의 이웃하는 셀들의 수를 나타내고,
Q_{RX, MIN}은 최소 요구되는 수신 신호 전력/품질 레벨이다.
Q_{RX, eNBon,k}는 폐쇄될, 그러나 UE가 핸드오버될 셀(이 셀로/셀로부터)에 대한 것은 아닌, 후보 셀의 이웃하는 셀인 셀의 가장 강한 수신 신호 전력을 의미하는 변수이다. 이 값은 UE 및 기지국 위치들에 좌우될 것이다. 통계치들에서 조건(Q_{RX, eNBon,k} > Q_{RX, MIN})이 거의 충족된다면, 이는 후보 셀이 폐쇄될 때, 폐쇄된 셀의 커버리지 영역이 이웃하는 셀들에 의해 커버될 것임을 의미한다.
사용자 장비 정전 확률은 자신들의 eNodeB 셀 신호를 검출할 수 있는, 그러나 다른 eNodeB들/셀들에 접속할 수 없거나 다른 eNB들/셀들로부터의 신호 세기/품질이 임계치 미만인 단말들의 수집 통계치들에 의해 추정된다.
정전 상태이거나 커버리지 내에 있는 각각의 UE에 대해 두 가지 옵션들이 존재한다. 정전 상태가 되기 위해서는, 모든 부등식들이 충족되어야 한다. 예를 들어, 10개의 UE들이 존재하며 2개의 UE들이 어떠한 다른 셀에도 접속할 수 없다면(모든 부등식들이 충족된다면), 이는 정전 확률이 20%임을 의미한다.
단계(3)에서, 후보 eNodeB 또는 셀이 오프 전환될 수 있는지 여부에 관한 결정이 이루어진다. 이는 아래 식(2)에 의존할 것이며,

여기서 Pr_{max outage}는 최대 허용 정전 확률이다.
정전 확률이 미리 정해진 정전 확률 임계치보다 낮다면, 후보 eNodeB 또는 셀이 오프 전환될 수 있다. 이는 단계(S4)에서 이루어진다. 이는 후보 eNodeB가 오프 전환되게 하기 위해 그 eNodeB에 제어 신호들을 전송하는 것을 수반할 것이다.
단지 예로서, 일 실시예에서 최대 정전 확률은 약 5%일 수 있다.
폐쇄될 셀들의 최적 결합을 얻기 위해 관리 엔티티에 의해 정전 확률(KPI)이 사용된다. 이는 커버리지 대 용량 제약들 및 에너지 절감 타깃들과 같은 운용자 정책들을 따름으로써 제어될 수 있다.
정전 확률이 미리 정해진 정전 확률 임계치보다 더 높다고 결정된다면, 단계(S5)에서 제어 엔티티가 주변 셀들 중 임의의 셀의 하나 또는 그보다 많은 파라미터들이 변경되게 할 수 있다. 다음에, 동작시, 변경된 파라미터들로 도 4의 방법이 반복된다. 이는 정전을 최소화하고 그리고/또는 폐쇄될 eNodeB들의 수를 최대화하기 위한 것이다.
제어될 수 있는 파라미터들은 기지국 송신 전력 레벨, 안테나 패턴, 안테나 방향, 안테나 수, 안테나 기울기와 같은 안테나 파라미터들, 업링크 전력 제어 파라미터들 및 핸드오버 파라미터들 중 하나 또는 그보다 많은 것을 포함한다.
파라미터의 변경 제어는 하나 또는 그보다 많은 UE들 중 어느 것이 정전을 겪을 가능성이 큰지에 대한 분석 및 오프 전환의 타깃이 되는 셀에서 그 UE들의 위치를 기초로 할 수 있다.
일부 실시예들에서는, 파라미터들을 변경하기 위해 제 2 임계치가 설정될 수 있다. 정전 확률이 이 제 2 임계치보다 더 낮지만 제 1 임계치보다는 더 높다면, 하나 또는 그보다 많은 파라미터들이 변경될 수 있다.
실시예들에서, eNodeB는 하나 또는 그보다 많은 셀들 또는 셀 섹터들을 제공할 수 있다. 일부 실시예들에서, 이러한 셀들 또는 셀 섹터들 중 하나 또는 그보다 많은 것이 오프 전환될 수 있다. 다른 실시예들에서는, 기지국 자체가 오프 전환될 수도 있다.
대안적인 실시예들은 UE 측정들을 기초로 후보 기지국이 오프 전환될지 여부를 결정하기 위해 서로 다른 방법들을 사용할 수 있다. 예를 들어, 셀 내의 모든 UE들이 적어도 하나의 다른 셀로부터 주어진 임계치를 초과하는 신호를 수신할 수 있다면, 그 후보 셀 또는 기지국이 오프 전환된다.
대안으로, 후보 기지국 또는 셀이 오프 전환되는 대신에 더 낮은 전력 모드가 될 수도 있다.
대안으로 또는 추가로, 후보 기지국 또는 셀의 안테나의 일부가 오프 전환되어, 셀의 커버리지를 축소시킬 수도 있다.
실시예들은 중앙 집중 및 분산 SON 기능 인스턴스들 모두에 적용될 수 있다.
대안으로 또는 추가로, 실시예들은 중계기 등의 오프 전환을 제어하는데 사용될 수도 있다.
또한, 상기는 예시적인 실시예들을 설명하지만, 본 명세서에서는 개시된 솔루션에 대해 본 발명의 범위를 벗어나지 않으면서 이루어질 수 있는 여러 가지 변형들 및 수정들이 존재한다는 점에 주의한다.
일반적으로, 다양한 실시예들은 하드웨어 또는 특수 목적용 회로들, 소프트웨어, 로직 또는 이들의 임의의 결합으로 구현될 수 있다. 본 발명이 이에 한정된 것은 아니지만, 실시예들의 일부 양상들은 하드웨어로 구현될 수 있는 한편, 다른 양상들은 제어기, 마이크로프로세서 또는 다른 컴퓨팅 디바이스에 의해 실행될 수 있는 펌웨어 또는 소프트웨어로 구현될 수 있다. 본 발명의 다양한 양상들이 블록도들, 흐름도들로서, 또는 다른 어떤 그림 표현을 사용하여 예시 및 설명될 수 있지만, 본 명서세에서 설명된 이러한 블록들, 장치, 시스템들, 기술들 또는 방법들은 한정적이지 않은 예들로서, 하드웨어, 소프트웨어, 펌웨어, 특수 목적용 회로들 또는 로직, 범용 하드웨어 또는 제어기 또는 다른 컴퓨팅 디바이스들, 또는 이들의 어떤 결합으로 구현될 수 있다고 잘 이해된다.
일부 실시예들은 모바일 디바이스의 데이터 프로세서에 의해, 예컨대 프로세서 엔티티에서 실행 가능한 컴퓨터 소프트웨어에 의해, 또는 하드웨어에 의해, 또는 소프트웨어와 하드웨어의 결합에 의해 구현될 수 있다.
추가로, 이 점에 있어서는, 도면들에서와 같은 로직 흐름의 임의의 블록들이 프로그램 단계들, 또는 상호 접속된 로직 회로들, 블록들 및 기능들, 또는 프로그램 단계들과 로직 회로들, 블록들과 기능들의 결합을 나타낼 수 있다는 점에 주의해야 한다. 소프트웨어는 메모리 칩들, 또는 프로세서 내에 구현된 메모리 블록들, 하드 디스크 또는 플로피 디스크들과 같은 자기 매체, 그리고 예를 들어 DVD 및 그의 데이터 변형들인 CD와 같은 광학 매체로서 그러한 물리적 매체 상에 저장될 수 있다.
메모리는 로컬 기술 환경에 적당한 임의의 타입일 수 있고, 임의의 적당한 데이터 저장 기술, 예컨대 반도체 기반 메모리 디바이스들, 자기 메모리 디바이스들 및 시스템들, 광 메모리 디바이스들 및 시스템들, 고정 메모리 및 착탈식 메모리를 사용하여 구현될 수 있다.
앞선 설명은 예시적이며 한정적이지 않은 예들로서 본 발명의 예시적인 실시예의 완전하고 유용한 설명을 제공하였다. 그러나 첨부 도면들 및 첨부된 청구항들과 함께 이해할 때, 앞선 설명을 고려하여 다양한 수정들 및 적응들이 관련 기술분야에서 통상의 지식을 가진 자들에게 명백해질 수 있다. 그러나 본 발명의 교시들의 모든 그러한 그리고 유사한 수정들은 첨부된 청구항들에서 정의된 바와 같은 본 발명의 범위 내에 여전히 속할 것이다. 실제로, 앞서 논의된 다른 실시예들 중 임의의 실시예 중 하나 또는 그보다 많은 실시예의 결합을 포함하는 추가적인 실시예가 존재한다.Next, certain exemplary embodiments are described in connection with a wireless or mobile communication system that serves mobile communication devices. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Before describing exemplary embodiments in detail, reference is made to FIGS. 1 and 2 to assist in understanding the underlying technology of the described examples. Some general principles of a wireless communication system, its access systems, Briefly explained.
The mobile communication device or user equipment 101, 102, 103, 104 is typically provided with wireless access via a similar radio transmitter and / or receiver node of at least one base station or access system. In FIG. 1, there are shown three neighboring overlapping access systems or radio service areas 100, 110, 120 provided by base stations 105, 106, 108.
It should be noted, however, that the communication system may be provided with any number of access systems instead of three access systems.
The access system may be provided by a cellular system, or by a cell of another system that enables the communication device to access the communication system. Base station sites 105, 106, and 108 may provide one or more cells. The base station may also provide a plurality of sectors, for example, three wireless sectors, each sector providing a cell or a sub-region of the cell. All sectors in a cell can be served by the same base station. A wireless link within a sector may be identified by a single logic identification belonging to that sector. Thus, the base station can provide one or more wireless service areas. Each mobile communication device 101, 102, 103, 104 and base stations 105, 106, 108 may simultaneously open one or more radio channels and may transmit signals to more than one source and / It is possible to receive signals from more sources.
Base stations 105,106 and 108 are generally configured to enable the management of mobile communications devices 101,102, 103,104 in communication with their operation and with base stations 105,106, And is controlled by an appropriate controller device 109, 107. Control devices 109 and 107 may be interconnected with other control entities. The control unit 109 may be provided with a memory capacity 301 and at least one data processor 302 in general. The control device 109 and functions may be distributed among the plurality of control units. In some embodiments, although not shown in FIG. 1, each of the base stations 105, 106, and 108 may include a controller 109, 107.
In some embodiments, the controller device may be provided by a Radio Network Controller (RNC) or a Base Station Controller (BSC). Some systems, such as LTE systems, do not have an RNC or BSC. However, the controller device may be a mobility management entity (MME) that can be used to control mobility.
Cell boundaries or edges are schematically shown in FIG. 1 for illustrative purposes only. It will be appreciated that the sizes and shapes of the cells or other wireless service areas may be significantly different from the omni-directional shapes of similar size in Fig. The degree of overlap of the cells may also be significantly different from that shown in FIG.
In particular, Figure 1 shows two wide area base stations 105, 106, which may be macro eNBs 105, 106. Macro eNBs 105 and 106 transmit and receive data across the entire coverage of each of the cells 100 and 110. [ 1 also shows, in some embodiments, a smaller base station or access point, which may be a pico eNB, a home or femto eNB, or a microcell 108. [ The coverage of the smaller base station 108 may generally be smaller than the coverage of the wide base stations 105, 106. The coverage provided by the smaller node 108 overlaps the coverage provided by the macro eNBs 105, 106. In some embodiments, the smaller node may be a femto or home eNB. The pico eNBs may be used to extend the coverage of the macro eNBs 105, 106 outside the original cell coverage 100, 110 of the macro eNBs 105, 106. The pico eNB may also be used to provide cell coverage to "gaps" or "shadows " where no coverage exists in existing cells 100 and 110 and / or may serve" hot spots ".
It should be noted that, in some embodiments, smaller eNBs may not be present. In alternate embodiments, there may be only smaller eNBs. In some embodiments, macro eNBs may not be present.
The communication devices 101, 102, 103 and 104 can access a communication system based on various access technologies such as code division multiple access (CDMA) or wideband CDMA (WCDMA) have. Other examples include time division multiple access (TDMA), frequency division multiple access (FDMA), and various methods thereof, such as interleaved frequency division multiple access (IFDMA) ), Single carrier frequency division multiple access (SC-FDMA), orthogonal frequency division multiple access (OFDMA), space division multiple access (SDMA), etc. .
Some non-limiting examples of recent developments in communication systems are Long Term Evolution (LTE) of the Universal Mobile Telecommunication System (UMTS) standardized by the 3rd Generation Partnership Project (3GPP). As described above, further development of LTE is referred to as LTE Advanced. Non-limiting examples of suitable access nodes are known as base stations in cellular systems, e.g., NodeB (NB) in the terminology of 3GPP specifications. LTE utilizes a mobile architecture known as Evolved Universal Terrestrial Radio Access Network (E-UTRAN). The base stations of these systems are known as evolved Node Bs (eNBs) and are known as user plane radio link control / media access control / physical layer protocols (RLC / MAC / PHY: Physical layer protocol) and control plane radio resource control (RRC) protocol terminations. Other examples of wireless access systems include those provided by base stations in systems based on technologies such as wireless local area network (WLAN) and / or Worldwide Interoperability for Microwave Access (WiMax).
In FIG. 1, the base stations 105, 106, and 108 of the access systems may be connected to a wider communication network 113. Controller devices 107 and 109 may be provided to coordinate the operation of the access systems. A gateway function 112 may also be provided to connect to another network via the network 113. [ The smaller base station 108 may also be connected to another network by an individual gateway function 111. The base stations 105, 106, and 108 may be connected to each other by a communication link for transmitting and receiving data. The communication link may be any suitable means for transmitting and receiving data between base stations 105, 106 and 108, and in some embodiments the communication link is an X2 link.
The other network may be any suitable network. Thus, a wider communication system may be provided by one or more interconnection networks and their elements, and one or more gateways may be provided to interconnect the various networks.
Mobile communication devices will now be described in more detail with reference to FIG. Figure 2 shows a schematic partial cross-sectional view of a communication device 101 that a user may use for communication. Such communication devices are often referred to as user equipment (UE) or terminals. Appropriate mobile communication devices may be provided by any device capable of transmitting and receiving wireless signals. Non-limiting examples include mobile stations (MS) such as mobile telephones or "smart phones", portable computers provided with wireless interface cards or other wireless interface facilities, personal data assistants (PDAs) provided with wireless communication capabilities data assistant, or any combination thereof. A mobile communication device may provide communication of data for communicating communications, such as voice, electronic mail (e-mail), text messaging, multimedia, and the like. Therefore, a large number of services can be supplied and provided to users through their communication devices. Non-limiting examples of such services include access to data communication network systems such as bi-directional or multi-directional calls, data communication or multimedia services or simply the Internet. The user may also be provided with broadcast or multicast data. Non-limiting examples of content include downloads, television and radio programs, videos, advertisements, various alerts, and other information.
The mobile device 101 may receive signals via a suitable device for receiving wireless signals via the air interface 207 and may transmit signals via appropriate devices for transmitting wireless signals. In FIG. 2, the transceiver device is schematically denoted by block 206. The transceiver device 206 may be provided, for example, by a radio portion and an associated antenna arrangement. The antenna arrangement may be located inside or outside the mobile device.
The mobile device also typically includes at least one data processing entity 201, at least one memory 202, and control of access to and communication with access systems and other communication devices, Other possible components 203 for use in software and hardware assisted execution of tasks designed to perform are provided. Data processing, storage and other associated control devices may be provided on the appropriate circuit boards and / or chipsets. This feature is indicated by reference numeral 204. [
The user may control the operation of the mobile device by a suitable user interface, such as keypad 205, voice commands, touch sensitive screen or pad, combinations thereof, and the like. A display 208, a speaker, and a microphone may also be provided. In addition, the mobile communication device may include suitable connectors (wired or wireless) for connecting to other devices and / or external accessories, such as a hands-free device, to the mobile communication device.
Self organizing networks have been proposed. One of the reasons why SONs have been proposed is for energy savings. With SON, one or more cells can be switched off when the traffic load is low. This may result in lower energy consumption on the network. Network operators, for example, may be able to reduce operating costs through lower electricity rates and provide more environmentally friendly services to others. This results in fewer CO 2 emissions due to lower energy consumption. ₂ Emissions. Alternatively or additionally, the use of self-organizing networks may be useful when one or more cells need to be shut down for maintenance, and the like. If the energy consumption is to be reduced, the cells can be switched off. Alternatively or additionally, a portion of the transmit / receive chain may be switched off. Additionally or alternatively, the transmit power may be adjusted. There may be other examples of ways that energy consumption can be reduced.
However, care must be taken to ensure that there are no coverage blanks or insufficient capacity for parts of the network. Thus, in some embodiments, care is taken to ensure that the correct cells to be turned off are identified, and that the corresponding correct selection for those cells that can compensate for the off-switching of that cell can be selected. Embodiments can ensure that certain quality of service can be maintained, even if the cell is switched off.
If the traffic load is low at a certain point in time and in the network, for example in a shopping center or shopping area at night, the base stations with a relatively small amount of traffic or a smaller coverage area can be closed. If the erroneous cells are switched off, high data rate services may not be provided in that area, or call or handover cuts may occur.
It has previously been suggested to use theoretical propagation models and quality of service estimates that use network planning tools to determine such base stations and times that can be switched off. However, this can be relatively costly and time consuming for operators to detect service outages by drive tests.
Currently, according to the handover mechanism of LTE, the user equipment not only has the strongest cell identity (cell ID) and the reference signal received power (RSRP) level for that cell, but also other strong cell identities and Will also report RSRP levels. Alternatively or additionally, the user equipment may report a reference signal received quality (RSRQ) for the serving cell and other strong cells. This information is reported to each serving eNB by each UE. In accordance with this handover mechanism, it is possible to modify the number of cells and which cells are reported by each UE. The eNB will therefore have time statistics of the reported measurements.
Alternatively or additionally, the information may be reported periodically. This periodic report can occur even if handover is not considered.
In one embodiment, this information is provided, for example, to the management entity shown in FIG. Such a management entity may be an element manager (EM) and a network management system (NMS). Alternatively, the entity may be provided, at least in part, by an eNB and / or a radio network controller (RNC). If functionality is provided by the eNB, data will be received from neighboring eNBs, for example, via an X2 connection or by any other suitable method.
Figure 3 shows an exemplary self-organizing network management controller device for network entities. 3, the controller device 309 is generally provided with at least one memory 301, at least one data processor 302, 303, and an input / output interface 304. In one embodiment, This interface can be configured to receive (directly or indirectly) UE measurement information from one or more eNBs.
In some embodiments, control device 309 is provided to a node and includes at least one memory and at least one computer readable storage medium having stored thereon computer program code that is capable of communicating with other network entities to cause the node to communicate control information, . ≪ / RTI > The control device may be interconnected with other control devices. The node may be a controller node, an RNC or an eNB, or may be at any other suitable node.
In embodiments, if the cell is to be potentially safely closed when handovers to or from the cell are reported, detectable neighbors must be reported. For potential cells to be closed, reports from all neighbors of that cell are required to make a secure decision. In some embodiments, reports may be additionally required for at least some of the neighbors of such neighboring cells. In some embodiments, data from a much larger area may be collected. In some embodiments, data from overlapping cells may also be collected.
In some embodiments, at least a third strong cell is detected for all handover regions of the cell to be closed through handover measurements. These third cells are neighbors of the cell to be closed, but may not be the neighbors of the cell (from / to this cell) to which the UE is to be handed over. This will ensure that there is at least a third cell that safely covers the area of the cell to be closed and the UE creates a secure handover area to the cell to be handed over (from / to this cell).
If a particular cell is closed, the collected statistics can be used to estimate the probability of user power failure. If the outage probability is acceptable, the cell can be safely closed. In some embodiments, the power failure probability is determined based on the collected statistics. In some embodiments, the cell can be safely closed. Depending on the probability, it may not be necessary to adjust the powers or slopes of any of the neighboring cells. If there is no significant risk of coverage gap between two or more of the closed cells, the probability of blackout can be tolerated.
If the probability is a certain level, antenna configurations such as antenna tilt, antenna pattern shape, antenna direction and / or antenna power may be changed in adjacent cells. Additional statistics may be collected, and if this reduces the probability of outage to acceptable levels, the cell may be switched off.
The method of the embodiment will now be described in more detail with reference to Fig.
At step Sl, user equipment measurements are received. These user equipment measurements may take any suitable format. In one embodiment, these measurements include cell identity information with associated signaling information.
This information provided by each user equipment may include measurements for the serving cell and at least one other cell. The at least one other cell may be predetermined, may be any cell with signal information exceeding the threshold, and / or may be n different cells selected in order of signal strength, and so on. n is an integer, and may be equal to or greater than one. For handover measurements, in some embodiments, there may be measurements from target cell measurements, from serving cell measurements, and from at least one other cell.
The signal information may include a measure of signal strength. In one embodiment, this information includes a reference signal received power (RSRP). This is the basic UE physical layer measurement and is the average of the downlink reference signals over the channel bandwidth. This information is obtained both in the idle state and in the connected state. In some standards, this information has already been collected for other purposes. It should be appreciated that any other suitable measure of signal strength, e.g., RSRQ, associated with the cell may alternatively or additionally be used.
Alternatively or additionally, the signal information may comprise a measure of signal quality. In one embodiment, this information may include a reference signal reception quality (RSRQ). In some embodiments, the RSRQ is defined as the ratio between the RSRP and the Received Signal Strength Indicator (RSSI). RSSI is the total received wideband power including all interference and thermal noise. RSRQ takes into account signal strength and interference level. Alternatively or additionally, other signal quality measurements may be obtained.
This information is received by eNodeBs from each user equipment. In embodiments, this information is provided to the management controller device.
User equipment measurements for a number of different cells are collected, and a power failure probability is determined based on the measurements in step S2. The determined probability is, in one embodiment, a key performance indicator (KPI). The outage probability for each eNodeB or cell is based on reported user equipment measurements. The electrostatic charge probability is defined by equation (1).

here
Pr is a probability.
Pr (UE in outage | eNB _off ) Is the probability that the user equipment will experience a power outage when the candidate eNodeB is switched off.
K represents the number of neighboring cells of the candidate cell to be closed,
Q _{RX, MIN} Is the minimum required received signal power / quality level.
Q _{RX, eNBon, k} Is a variable that means the strongest received signal power of a cell that is to be closed but not the cell to which the UE is to be handed over (from / to the cell), which is the neighboring cell of the candidate cell. This value will depend on the UE and base station locations. In the statistics, the condition (Q _{RX, eNBon, k} > Q _{RX, MIN} ) Is nearly satisfied, this means that when the candidate cell is closed, the coverage area of the closed cell will be covered by the neighboring cells.
The user equipment outage probability is estimated by collection statistics of terminals that are able to detect their eNodeB cell signal, but are not able to connect to other eNodeBs / cells or whose signal strength / quality from other eNBs / cells is below the threshold.
There are two options for each UE in the outage or in coverage. In order to be in the blackout state, all inequalities must be met. For example, if there are 10 UEs and two UEs can not connect to any other cell (if all inequalities are met), this means that the power failure probability is 20%.
In step (3), a determination is made as to whether the candidate eNodeB or cell can be switched off. This will depend on equation (2) below,

Where Pr _{max outage} Is the maximum allowed outage probability.
If the outage probability is lower than the predetermined outage probability threshold, the candidate eNodeB or cell may be switched off. This is done in step S4. This will involve sending control signals to the eNodeB to allow the candidate eNodeB to be switched off.
By way of example only, in one embodiment the maximum outage probability may be about 5%.
A power failure probability (KPI) is used by the management entity to obtain the optimal combination of cells to be closed. This can be controlled by following operator policies such as coverage versus capacity constraints and energy saving targets.
If it is determined that the outage probability is higher than the predetermined outage probability threshold, in step S5, the control entity may cause one or more parameters of any of the surrounding cells to change. Next, in operation, the method of FIG. 4 is repeated with the changed parameters. This is to minimize power outages and / or maximize the number of eNodeBs to be closed.
The parameters that can be controlled include one or more of base station transmit power level, antenna pattern, antenna direction, antenna number, antenna parameters such as antenna tilt, uplink power control parameters and handover parameters.
The change control of the parameters may be based on the location of the UEs in the target cell of the analysis and off transition of which one or more of the UEs are likely to suffer power failure.
In some embodiments, a second threshold may be set to change the parameters. If the outage probability is lower than this second threshold but higher than the first threshold, one or more parameters may be changed.
In embodiments, the eNodeB may provide one or more cells or cell sectors. In some embodiments, one or more of these cells or cell sectors may be switched off. In other embodiments, the base station itself may be switched off.
Alternate embodiments may use different methods to determine whether the candidate base station is switched off based on UE measurements. For example, if all the UEs in a cell can receive a signal exceeding a given threshold from at least one other cell, the candidate cell or base station is switched off.
Alternatively, the candidate base station or cell may be in a lower power mode instead of being switched off.
Alternatively or additionally, a portion of the antenna of the candidate base station or cell may be switched off to reduce the coverage of the cell.
Embodiments may be applied to both centralized and distributed SON function instances.
Alternatively or additionally, the embodiments may be used to control an off switch of a repeater or the like.
In addition, while the foregoing describes exemplary embodiments, it should be noted that there are numerous variations and modifications that may be made to the disclosed solution without departing from the scope of the invention.
In general, the various embodiments may be implemented in hardware or special purpose circuits, software, logic, or any combination thereof. While the invention is not so limited, some aspects of embodiments may be implemented in hardware, while other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor, or other computing device. While various aspects of the present invention may be illustrated and described using block diagrams, flowcharts, or any other pictorial representation, such blocks, apparatus, systems, techniques, or methods described in this specification are not limiting By way of illustration, it is to be understood that the invention may be implemented in hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controllers or other computing devices, or any combination thereof.
Some embodiments may be implemented by a data processor of a mobile device, e.g., by computer software executable on a processor entity, or by hardware, or by a combination of software and hardware.
Additionally, in this regard, it should be understood that any block of logic flow, such as those in the Figures, may be programmed steps, or interconnected logic circuits, blocks and functions, or program steps and logic circuits, It should be noted that it can represent a combination of functions. The software may be stored on memory devices, such as memory chips, memory blocks implemented in a processor, magnetic media such as hard disks or floppy disks, and optical media such as CDs, e.g., DVDs and data modifications thereof .
The memory may be any type suitable for the local technical environment and may include any suitable data storage technology such as semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory ≪ / RTI >
The foregoing description is provided by way of example and not of limitation, and is intended to provide a complete and illustrative description of an exemplary embodiment of the invention. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. However, all such and similar modifications of the teachings of the present invention will still fall within the scope of the invention as defined in the appended claims. Indeed, there are additional embodiments that include combinations of one or more of any of the other embodiments discussed above.

Claims (15)

A method for determining if a cell can be used in a reduced energy mode,
Receiving signal information for at least one cell from a plurality of user equipments;
Using the information to determine an outage probability for the user equipment; And
Inserting a candidate cell into a reduced power mode and ensuring that another cell covers an area of the candidate cell before the candidate cell enters the reduced power mode when the power failure probability is lower than a threshold; or
Causing the at least one parameter of at least one neighboring cell to change if the probability of failure is higher than a threshold,
Lt; / RTI >
Wherein when the electrostatic probability is higher than a threshold value, after the at least one parameter is changed,
A method for determining if a cell can be used in a reduced energy mode. The method according to claim 1,
Wherein the signal information includes handover information,
A method for determining if a cell can be used in a reduced energy mode. 3. The method according to claim 1 or 2,
Wherein the signal information comprises at least one of signal strength information and signal quality information,
A method for determining if a cell can be used in a reduced energy mode. 3. The method according to claim 1 or 2,
And comparing the signal information for the at least one cell to a minimum value for the signal information.
A method for determining if a cell can be used in a reduced energy mode. 3. The method according to claim 1 or 2,
Receiving, from each of the plurality of user equipments, signal information for a serving cell and at least one other cell different from the candidate cell;
A method for determining if a cell can be used in a reduced energy mode. 3. The method according to claim 1 or 2,
Receiving information about at least one cell neighboring the candidate cell, wherein a determination is made as to whether the candidate cell enters a reduced power mode,
A method for determining if a cell can be used in a reduced energy mode. delete The method according to claim 1,
Determining the power failure probability depends on information about one or more user equipment receiving only signals from the serving cell,
A method for determining if a cell can be used in a reduced energy mode. delete 3. The method according to claim 1 or 2,
Wherein the reduced power mode comprises switching off the cell.
A method for determining if a cell can be used in a reduced energy mode. delete The method according to claim 1,
Wherein the at least one parameter comprises at least one of an antenna configuration, an antenna orientation, a transmit power, and an uplink power control parameter.
A method for determining if a cell can be used in a reduced energy mode. 22. A computer readable storage medium,
Comprising computer-executable instructions for causing the method of claim 1 or claim 2 to be performed upon execution,
Computer readable storage medium. An apparatus for determining if a cell can be used in a reduced energy mode,
Means for receiving signaling information for at least one cell from a plurality of user equipments;
Means for using the information to determine a power failure probability for the user equipment; And
Inserting a candidate cell into a reduced power mode if the power failure probability is lower than a threshold and ensuring that another cell covers an area of the candidate cell before the candidate cell enters the reduced power mode,
Means for causing at least one parameter of at least one neighboring cell to change when said probability of failure is above a threshold;
/ RTI >
Receiving the signal information after the at least one parameter is changed if the power failure probability is higher than a threshold value; using the information; and determining whether the power failure probability is lower or higher than the threshold value, To enter a reduced power mode and to ensure that another cell covers the area of the candidate cell, or to cause the at least one parameter to change,
Wherein the cell is in a reduced energy mode. 15. The method of claim 14,
Wherein the means for use determines the power failure probability according to information on one or more user equipments receiving only signals from a serving cell,
Wherein the cell is in a reduced energy mode.

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